# -*- coding:utf-8 -*-
a=10
def foo():
     global  a
     a = 100

print(a)
foo()
print(a)

start = 12
def countdown(start):
    i = [start]
    def decrement():
        i[0] -= 1
        return i[0]
    return decrement

a = countdown(start)
print('start:',a())